Shoe clamping mechanism for power tool and power tool incorporating such mechanism

Abstract

A mechanism is disclosed for clamping a jigsaw ( 1 ) shoe in a desired position relative to the body of a power tool. A plurality of gear ( 22, 26 ) teeth are used to allow greater torque and access as compared to prior art clamping mechanisms.

1. A shoe clamping mechanism for a power tool having a housing, a working member extending from the housing, and a shoe for engaging a workpiece and adapted to be clamped in a plurality of orientations relative to the working member, the mechanism comprising:
 clamping means having a clamping portion and a mounting portion, wherein the clamping means is adapted to be mounted to the tool such that rotation of said mounting portion relative to the housing about a first axis causes movement of said clamping portion between a first position in which said shoe is pivotable relative to the working member and a second position in which said shoe is clamped in position relative to said working member; 
 actuating means adapted to be pivoted about a second axis, substantially parallel to said first axis and displaced therefrom; and 
 torque adjusting means connected to said actuating means and said clamping means wherein application of a first torque to pivot said actuating means about said second axis causes application of a second torque, higher than said first torque, to said clamping means to rotate said mounting portion about said first axis. 
 
   
   
     2. A mechanism according to  claim 1 , wherein the torque adjusting means comprises a gear mechanism. 
   
   
     3. A mechanism according to  claim 2 , wherein the gear mechanism comprises a first gear having a plurality of first gear teeth and mounted to said actuating means and a second gear having a plurality of second gear teeth and connected to said mounting portion, wherein the number of said second gear teeth is larger than the number of said first gear teeth. 
   
   
     4. A mechanism according to  claim 1 , wherein the clamping portion comprises a clamping plate restrained in use from rotating about said first axis. 
   
   
     5. A mechanism according to  claim 4 , further comprising a track for receiving said clamping plate and fixed in position relative to said housing. 
   
   
     6. A mechanism according to any  claim 1 , wherein the mounting portion includes a thumb wheel. 
   
   
     7. A mechanism according to  claim 1 , wherein the mounting portion includes a screw thread. 
   
   
     8. A tool comprising a housing, a working member extending from the housing, a shoe engagable with a workpiece and clampable in a plurality of orientations relative to the working member, and a shoe clamping assembly comprising:
 a clamp; 
 a mount coupling with said clamp, rotation of said mount relative to the housing about a first axis causing movement of said clamp between a first position in which said shoe is pivotable relative to the working member and a second position in which said shoe is clamped in position relative to said working member; 
 a thumb wheel pivotable about a second axis, substantially parallel to said first axis and displaced therefrom; 
 a gear mechanism connected between said thumb wheel and said clamp, wherein application of a first torque to pivot said thumb wheel about said second axis causes application of a second torque to said mount to rotate said mount about said first axis. 
 
   
   
     9. A tool according to  claim 8 , wherein the shoe comprises a first arcuate portion for cooperating with a second arcuate portion on the housing. 
   
   
     10. A tool according to  claim 9 , wherein the shoe plate comprises an aperture adapted to receive said clamp. 
   
   
     11. The tool recited in  claim 8 , said gear mechanism comprising a first gear connected to said thumb wheel and a second gear connected to said mount. 
   
   
     12. A tool according to  claim 11 , wherein said tool is a reciprocating saw.